Environmentally hazardous fluids such as acids, oils, and toxins, which can cause serious harm to the environment often need to be pumped through fluid flow systems from one location to another. Centrifugal pumps typically including a motor driven impeller affixed to the pump shaft are typically utilized to pump these fluids. The pump shafts of such pumps are generally rotatably supported against radial movement and vibration by conventional pump shaft bearings (e.g. ball bearings). These bearings must be continually lubricated throughout the operation of the pump in order to maintain an adaptable operating life of the bearings and corresponding pump.
Conventional lubricating fluid such as oil is used to lubricate such pump shaft bearings, this fluid typically being housed in a bearing lubrication chamber surrounding the pump shaft. When pumping such dangerous flow materials, it is important that neither the lubricating fluid (e.g. oil) nor the fluid being pumped escape into the atmosphere or adjacent fragile pump areas. Thus, seals must be provided.
Conventional pumps typically include supporting shaft ball bearings disposed within a lubrication chamber, the bearings for rotatingly supporting the shaft as it is driven by a motor. Such bearings are generally lubricated by having the oil level within the lubrication chamber maintained at a level about half-way up the bottom bearing ball. The maintaining of the lubricating oil level half-way up the bottom bearing ball necessarily means that when the shaft and supporting bearings are rotated, the bearing balls must continuously plow through the lubricating oil in which they are partially submerged. This results in significant heat generation due to the friction created by the bearing balls forever passing through the viscous oil.
Furthermore, when the oil level is disposed halfway up the bearing balls or higher as is conventional in the art, dirt or contaminants present within the oil are easily permitted to make their way into the bearing raceways through which the bearing balls circumferentially rotate or roll around the pump shaft. As will be recognized by those of skill in the art, the allowance of dirt or other contaminants into the bearing raceways often leads to premature failure of the bearings and increased maintenance. Accordingly, it would satisfy a long-felt need in the art if a pump were to be developed so as to include an oil misting or lubrication chamber wherein the lubricating fluid (e.g. oil) level was disposed below the bearing balls, thereby reducing heat generation within the lubrication chamber and limiting the amount of dirt or other contaminants permitted to make their way into the bearing raceways.
Commonly owned U.S. Pat. No. 5,261,676, which is prior art to the instant invention due to an offer of sale more than one year before the instant filing date, discloses a centrifugal environmentally sealed pump including a bearing lubrication chamber. Disposed within the lubricated chamber is an oil dispenser affixed to the pump shaft for rotation therewith. The rotating dispenser has a plurality of hoods which protrude therefrom, these hoods acting to pick up and disperse (i.e. splash and/or mist) the lubricating oil throughout the chamber so as to lubricate the pump shaft bearings therein. The hoods affixed to the rotating dispenser protrude so as to dip below the lubricating oil level within the chamber as the dispenser is rotated thus scooping the oil from the reservoir area and dispersing it throughout the chamber and toward the adjacent bearings.
While the bearing lubrication system of the '676 patent is excellent and provides good results, the hoods of the dispenser are required to plow through the lubricating oil housed within the lubrication chamber in order to properly disperse the oil throughout the chamber. This generates undesirable heat within the lubrication chamber thus requiring the bearings to run at an increased temperature thereby resulting in increased maintenance requirements. Furthermore, as a result of the hoods of the '676 dispenser picking up the lubricating oil and subsequently delivering it throughout the chamber, dirt and other contaminants such as rust, carbonized particles, etc. are directed toward the bearings along with the picked up lubricating oil.
Additionally, the dispenser of the '676 patent directs lubricating fluid toward only one side of each shaft bearing. After reaching the bearing balls of a particular bearing, the lubricating fluid or oil relies upon rotation of the bearings within their respective raceways for allowing the oil to migrate throughout the entire bearing assembly. Thus, with respect to the double row bearing disposed between the dispenser and motor in the '676 patent, the bearing furthest from the dispenser and lubrication chamber is only lubricated by way of oil or lubricating fluid which makes its way through the first bearing row, the first bearing row, of course, being disposed between the lubrication chamber and the second bearing row.
Bearing frame seals are provided adjacent both the single and double row bearing assemblies of the '676 patent, these bearing frame seals being positioned on the side of the bearings located furthest from the lubrication chamber. The purpose of these bearing frame seals is to prevent the oil or lubricating fluid within the bearings from leaking or migrating into other parts of the pump or the surrounding environment. As a result, the lubricating fluid or oil which ends up sandwiched between the bearing balls and an adjacent bearing frame seal often remains there for an extended period of time without being circulated back into the lubrication chamber. This, of course, may result in dirt or contaminant particles being trapped within the bearing assembly for extended periods of time as well as the lubricating oil or fluid disposed between the bearing balls and adjacent bearing frame seals prematurely breaking down. Thus, it would satisfy a long-felt need in the art if the lubricating fluid disposed between the bearing balls and adjacent bearing frame seals furthest from the lubrication chamber could be circulated to and from the lubrication chamber so as to keep clean, cool, and effective lubricating fluid adjacent the exterior or outer sides of the bearing balls at all times.
It is apparent from the above that there exists a need in the art for a pump including a bearing lubrication system wherein: 1) the lubricating fluid dispenser does not contact or dip below the lubricating fluid level within the lubrication chamber thereby allowing the bearings and pump shaft to run at lower operating temperatures within the lubrication chamber; 2) the lubricating fluid level is maintained at a level below the bearing balls disposed in the lubrication chamber so as to reduce heat generation; 3) both sides of the single and/or double row bearing assemblies are simultaneously lubricated by way of lubricating fluid so as to ensure prompt and constant bearing lubrication; and 4) clean, cool, and effective lubricating fluid is maintained along the exterior or outer side of the bearing assemblies between the bearing frame seals and adjacent bearing balls so as to extend the life of the bearings.
It is the purpose of this invention to fulfill the above-described needs in the art, as well as other needs apparent to the skilled artisan from the following detailed description of this invention.